[Intel-gfx] [PATCH] drm/i915: Introduce mapping of user pages into video memory (userptr) ioctl

[Daniel Vetter]

On Wed, Jan 29, 2014 at 10:53 PM, Chris Wilson <chris at chris-wilson.co.uk> wrote:
> On Wed, Jan 29, 2014 at 09:25:51PM +0100, Daniel Vetter wrote:
>> So originally I've thought we need this due to the massive overhead of the
>> mmu notifier. But now with the nice shared mmu notifiers I've thought that
>> overhead is gone I prefer to also ditch this option.
>>
>> Same goes about the MMU_NOTIFIER conditional code, imo we simply should
>> select this - most distros will have it anyway and users will be really
>> suprised if they lose userspace driver features for seemingly irrelevant
>> reasons.
>
> Seriously? You think the overhead is magically gone?

Well the once-per-process overhead is still there, and imo it's ok to
eat that. But the complaints I've heard concerned the per-object
overhead, so I wonder how much of that is still relevant.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch